For the beverage, gas shall be mixed into the liquid beverage usually. For example, much carbon dioxide shall be dissolved into the beverage when a carbonated beverage is prepared, and water and carbon dioxide are generally pressed into the gas-liquid mixing device of the beverage to achieve dissolution of carbon dioxide in water in the gas-liquid mixing device of the beverage. A main structure in the prior art is as follows: a liquid pipeline extends into a container of the gas-liquid mixing device, a micropore penetrating a pipe wall is formed in a side wall of the pipeline to form a venturi pipe structure, a high-pressure water flow in the pipeline generates negative pressure at a micropore area, and the negative pressure sucks gas outside the pipeline into the pipe to be mixed and dissolved with the water.
The defects in the prior art lie in that liquid in the pipeline is not subjected to low temperature treatment and has higher temperature; the temperature of the water will also rise after pressurization; the high temperature water reduces a dissolution rate of the gas; the gas is not subjected to cooling treatment, a content of the gas dissolved into the liquid is limited, and the quality of the beverage is influenced; in addition, the prepared beverage is higher in temperature and must be cooled, and an external refrigeration device is required to cool the prepared beverage, so that the cost is increased, the size of beverage preparation equipment is also increased, and an application scope of the equipment is reduced.